EP0504651A1 - Film de polyester pour bande magnétique - Google Patents

Film de polyester pour bande magnétique Download PDF

Info

Publication number
EP0504651A1
EP0504651A1 EP92103616A EP92103616A EP0504651A1 EP 0504651 A1 EP0504651 A1 EP 0504651A1 EP 92103616 A EP92103616 A EP 92103616A EP 92103616 A EP92103616 A EP 92103616A EP 0504651 A1 EP0504651 A1 EP 0504651A1
Authority
EP
European Patent Office
Prior art keywords
polyester
film
young
modulus
layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP92103616A
Other languages
German (de)
English (en)
Other versions
EP0504651B1 (fr
Inventor
Shigeo Utsumi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Polyester Film Corp
Original Assignee
Mitsubishi Polyester Film Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Polyester Film Corp filed Critical Mitsubishi Polyester Film Corp
Publication of EP0504651A1 publication Critical patent/EP0504651A1/fr
Application granted granted Critical
Publication of EP0504651B1 publication Critical patent/EP0504651B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73923—Organic polymer substrates
    • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
    • G11B5/73929—Polyester substrates, e.g. polyethylene terephthalate comprising naphthalene ring compounds, e.g. polyethylene naphthalate substrates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73923—Organic polymer substrates
    • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
    • G11B5/73931—Two or more layers, at least one layer being polyester
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/91—Product with molecular orientation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31786—Of polyester [e.g., alkyd, etc.]

Definitions

  • the present invention relates to a polyester film for a magnetic tape. More particularly, the present invention relates to a polyester film which has high strength in both longitudinal and transverse directions and excellent abrasion resistance and is suitable as a base film of a magnetic tape.
  • One object of the present invention is to provide a base film for a magnetic tape, which does not suffer from the problem of fallen particles and the abrased powder.
  • Another object of the present invention is to provide a base film for a long-play video tape.
  • a laminated polyester film for a magnetic tape which film comprises a layer of a crystalline polyester (A) and a layer of a polyester (B) which is laminated on at least one surface of the layer of the polyester (A) and has a melting point lower than that of the polyester (A), and which film has a Young's modulus of at least 600 kg/mm2 in both longitudinal and transverse directions.
  • the polyester (A) used in the polyester film of the present invention may be a polymer prepared through a polycondensation reaction of an aromatic dicarboxylic acid (e.g. terephthalic acid and naphthalene-2,6-dicarboxylic acid) with an aliphatic glycol (e.g. ethylene glycol, diethylene glycol, tetramethylene glycol and neopentyl glycol).
  • aromatic dicarboxylic acid e.g. terephthalic acid and naphthalene-2,6-dicarboxylic acid
  • an aliphatic glycol e.g. ethylene glycol, diethylene glycol, tetramethylene glycol and neopentyl glycol
  • Specific examples of the polyester (A) are polyethylene terephthalate (PET) and polyethylene-2,6-naphthalene dicarboxylate (PEN).
  • a polymer prepared through a copolymerization with an aromatic or aliphatic dicarboxylic acid or diol in such amount that the crystallinity is not decreased, for example, at most 10 % by mole, preferably at most 5 % by mole.
  • other polymer such as a polyamide, a polyolefin and a polycarbonate in an amount of not larger than 10 % by weight, it is not preferable to use the other polymer in an amount such that the crystallinity is extremely decreased or the film surface is extremely roughened after the film preparation.
  • the polyester (B) used in the polyester film of the present invention has a lower melting point than the polyester (A).
  • the polyester (B) is preferably a copolymeric polyester.
  • the copolymeric polyester may be a copolymerization product having a base polyester component unit used in the polyester (A) such as an ethylene terephthalate unit and an ethylene-2,6-naphthalate unit with at least one other component unit.
  • the copolymerizable component may be at least one dicarboxylic acid such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, 1,10-decane dicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid and diphenylether dicarboxylic acid; or at least one diol such as neopentyl glycol, 1,4-butane diol, trimethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, polyalkylene glycol and 1,4-cyclohexane dimethanol.
  • dicarboxylic acid such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, 1,10-decane dicarboxylic acid, phthalic acid,
  • a hydroxycarboxylic acid such as p-hydroxybenzoic acid and p-hydroxyethoxybenzoic acid
  • a monofunctional compound such as benzoic acid, benzoylbenzoic acid and methoxypolyalkylene glycol
  • a polyfunctional compound such as glycerol and pentaerythritol can be used so long as the product has a substantially straight chain.
  • a content of the copolymerizable component which is other than the base components of the polyester (A) and used in the copolymer (B) is such that a total (T + W) of a ratio [T (% by mole)] of the carboxylic acid in such copolymerizable components to the total amount of all carboxylic acids and a ratio [W (% by mole)] of the diol component in such copolymerizable component to the total amount of all the diols is usually from 6 to 40 % by mole, preferably 10 to 40 % by mole.
  • the amount of such copolymerizable component is smaller than 6 % by mole, effects on the prevention of particle drop off and the improvement of abrasion resistance are not expected.
  • the amount is larger than 40 % by mole, the formation of the laminate film is difficult.
  • the polyester used in the present invention may usually contain fine particles such as an organic lubricant and inorganic lubricant to improve a sliding property. If necessary, an additive such as a stabilizer, a pigment, an antioxidant, an antifoamer and an antistatic agent may be added.
  • an additive such as a stabilizer, a pigment, an antioxidant, an antifoamer and an antistatic agent may be added.
  • fine particles giving the sliding property are inert external particles such as kaolin, clay, calcium carbonate, silicon oxide, spherical silica, calcium terephthalate, aluminum oxide, titanium oxide, calcium phosphate, lithium fluoride and carbon black; and internal particles formed in the polymer during the polymer preparation by a high melting point organic compound which is not meltable during the film melt preparation of the polyester resin, a cross-linked polymer and a metal compound catalyst (for example, an alkaline metal compound and an alkaline earth metal compound) used during the polyester preparation.
  • inert external particles such as kaolin, clay, calcium carbonate, silicon oxide, spherical silica, calcium terephthalate, aluminum oxide, titanium oxide, calcium phosphate, lithium fluoride and carbon black
  • the polyester layer (A) does not necessarily contain the inert particles depending on a form of lamination, for example, when the polyester layer (A) is sandwiched between a pair of the polyester layers (B). If desired, the polyester layer (A) may contain the inert particles having an average particle size of 0.007 to 5 ⁇ m, in particular 0.02 to 1.5 ⁇ m in an amount of 0.001 to 1.00 % by weight, preferably 0.1 to 0.8 % by weight.
  • An average particle size of the inert particles contained in the polyester layer (B) is not limited and is preferably from 0.007 to 3.5 ⁇ m, in particular from 0.02 to 2 ⁇ m in view of good rolled form of the film.
  • a content of the particles is usually from 0.001 to 40 % by weight, preferably from 0.005 to 15 % by weight.
  • the polyester film of the present invention has the Young's modulus of at least 600 kg/mm2 in both longitudinal and transverse directions.
  • the longitudinal Young's modulus is at least 600 Kg/mm2 and the transverse Young's modulus is at least 700 kg/mm2.
  • the Young's modulus both in the longitudinal and transverse directions is at least 700 kg/mm2.
  • the longitudinal Young's modulus is at least 700 kg/mm2 and the transverse Young's modulus is at least 800 kg/mm2. If the Young's modulus in either of the longitudinal and the transverse direction is less than 600 kg/mm2, the film cannot be practically used.
  • the laminated film may be prepared by any one of the conventional methods such as coextrusion, extrusion-lamination, dry lamination and the like.
  • coextrusion is advantageous in the preparation of a thin copolymer film and preferable in view of the productivity. Therefore, the following explanation is made by making reference to the coextrusion.
  • the polyester (A) and polyester (B) optionally containing the inorganic particles in a suitable amount are dried using a hopper dryer, a paddle dryer, a vacuum dryer or the like, and then molten at 200 to 320°C in separate extruders. Then, the polyesters are flowed together in a pipe or a nozzle, extruded in two layers or three layers, and quenched to prepare an unstretched film.
  • a conventional method such as a T-die method and a tubular method can be used.
  • a ratio of the thicknesses in a laminate film can be varied.
  • the unstretched film When the T-die method is used to prepare the unstretched film, a film with a uniform thickness can be obtained by using a so-called electrostatic pinning method. Then, the unstretched film is stretched bin longitudinal and transverse directions at a draw ratio of at least 2.0 at a temperature of from (Tg A - 10) to (Tc A - 10) °C [Tg A : a glass transition temperature of the polyester (A), Tc A : a crystallization temperature of the polyester (A)].
  • the film is again successively biaxially stretched at a temperature of from (Tg A + 10) to (Tm A - 40) °C at a longitudinal draw ratio of from 1.05 to 2.5 and a transverse draw ratio of from 1.05 to 2.5 and then heat-set.
  • the heat set is preferably carried out at a temperature from (Tm B - 10) to Tm A °C, more preferably from Tm B to Tm A °C, in particular from (Tm B + 5) to Tm A °C [Tm B : a melting point of the polyester (B)].
  • Tm B a melting point of the polyester
  • the heat set is usually carried out with maintaining the film in the fixed state.
  • the film can be shrunk or tentered in the longitudinal and/or transverse directions of the film in an amount of not larger than 20 % during the heat treatment or during cooling after the heat treatment.
  • a corona discharge treatment can be applied to one or both of the film sides so that the adhesion property of the film to a magnetic layer and the like are improved.
  • a coating can be conducted on one or both of film sides so that an adhesion property, an antistatic property, an easy sliding property and a light shielding property are improved.
  • the film prepared as stated above is wound to give a product.
  • the laminate film of the present invention is based on a two layer film consisting of layers (A) and (B), the film of the present invention may have more than two layers.
  • the kinds, particle sizes and amounts of the particles to be contained in one of the polyester layers (B) may be the same as or different from those in the other in view of the end use of the polyester film.
  • one of the polyester layers (B) contains a smaller amount of the particles, for example, 0.007 to 0.5 % by weight, while the other contains a larger amount of the particles, for example, 0.5 to 15 % by weight.
  • Such film can be used as a base film of a nonback-coated magnetic tape.
  • a ratio (t/d) of the thickness (t) of the layer (B) to the average particle size (d) of the inert particles in the layer (B) is preferably from 0.1 to 10, more preferably from 0.2 to 2.0, most preferably from 0.3 to 1.0.
  • the value of t/d is outside the above range, the rolled form in the rolled product of the film tends to be unsatisfactory.
  • the degree of planar orientation ⁇ P is not larger than 0.100, preferably not larger than 0.050, more preferably not larger than 0.030, most preferably not larger than 0.010.
  • the film has poor abrasive resistance.
  • a thickness of the polyester layer (B) is usually 5 ⁇ m or less, preferably from 0.005 to 2 ⁇ m, more preferably from 0.01 to 1 ⁇ m, in particular from 0.01 to 0.7 ⁇ m. When the thickness of the polyester layer (B) exceeds 5 ⁇ m, the strength of the polyester film decreases.
  • a contamination degree of a roller surface contacting to a base film was evaluated using a five step miniature supercalender.
  • the supercalender was five-step calender consisting of mirror finished metal rollers and polyester composite resin rollers. In each roller, a temperature was fixed at 95 °C, a line pressure was fixed at 250 kg/cm and a travel velocity was fixed at 80 m/min. The magnetic tape of 5000 m was repeatedly traveled seven times, and white powder adhered to the resin roller was visually evaluated as follows:
  • the center line average roughness was measured according to JIS B-0601-1976, with necessary modifications.
  • the measuring conditions were the use of a contact needle having having a tip radius of 2 ⁇ m, 30 mg of probe contact pressure, 80 ⁇ m of cutoff, and 2.5 mm of a measuring length.
  • a film was contacted at a winding angle of 135° ( ⁇ ). With applying a load of 53 g (T2) to one end of the film, the film was moved at a rate of 1 m/min. and a resistance (T1 g) at the other end was measured.
  • Terephthalic acid (87 parts by weight) was esterified with ethylene glycol (42 parts by weight) under an atmospheric pressure at 260 °C in the presence of bis-( ⁇ -hydroxyethyl) terephthalate oligomer (100 parts by weight) to prepare a polyester oligomer having an esterification rate of 97 %. Then, an ethylene glycol slurry of spherical silica particles having an average particle size of 0.3 ⁇ m was added in an amount of 0.35 % by weight based on the polyester.
  • polyester (I) ethyl acid phosphate (0.014 part by weight), antimony trioxide (0.022 part by weight) and magnesium acetate (0.086 part by weight) were added to perform a polycondensation reaction so as to prepare a polyester having an intrinsic viscosity of 0.660 (polyester (I)).
  • the polyester (I) was dried and extruded at 295 °C by an extruder to prepare a sheet and an amorphous sheet was prepared by the electrostatic pinning cooling method.
  • the resultant amorphous sheet was firstly 2.5 times stretched at 100 °C in a longitudinal direction, and then 1.8 times at 90 °C in the same direction. Then, the sheet was 3.62 times stretched at 105 °C in a transverse direction, and again 1.06 times at 125 °C in the longitudinal direction and 1.32 times at 190 °C in the transverse direction, followed by heat setting at 220 °C to obtain a film having a thickness of 10 ⁇ m.
  • polyester (B) was used a copolymeric polyester (II) in which the dicarboxylic acid component consists of 80 % by mole of a terephthalic acid units and 20 % by mole of isophthalic acid units and the diol component consists of 100 % by mole of ethylene glycol units, and which contains the same spherical silica particles as used in Comparative Example 1 and has an intrinsic viscosity of 0.70.
  • polyesters (I) and (II) were dried and molten in separate extruders at 287 °C, flowed together in a pipe and coextruded in the form of a laminate consisting of an inner layer of the polyester (I) and outer layers of the polyester (II), followed by quenching to obtain an unstretched film.
  • the unstretched film was stretched in the manner as in Comparative Example 1 to obtain a film having a thickness of 10 ⁇ m.
  • the film consisted of three layers having thicknesses of 0.1 ⁇ m, 9.8 ⁇ m and 0.1 ⁇ m (Example 1) or 0.05 ⁇ m, 9.9 ⁇ m and 0.05 ⁇ m (Example 2).
  • a magnetic paint was coated to fabricate a magnetic tape.
  • the calendering step no white powder was generated and the magnetic tape had good properties.
  • dimethyl naphthalene-2,6-dicarboxylate 100 parts by weight
  • ethylene glycol 60 parts by weight
  • calcium acetate monohydrate 0.1 part by weight
  • titanium oxide having an average particle size of 0.3 ⁇ m (0.40 part by weight) and antimony trioxide (0.04 part by weight) were added to initiate the polycondensation reaction. That is, the temperature was gradually raised to 290°C while the pressure was gradually decreased from the atmospheric pressure to 0.3 mmHg.
  • the above raw material (III) was dried and extruded at 295 °C by an extruder to prepare a sheet and an amorphous sheet was prepared by the electrostatic pinning cooling method.
  • the polymer was filtered through a two-step filter corresponding to 2000 mesh and 2500 mesh.
  • the amorphous film was 3.0 times stretched at 135 °C in the longitudinal direction and then 3.95 times at 135 °C in the transverse direction.
  • the biaxially stretched film was again 1.40 times stretched at 138 °C the longitudinal direction and then 1.22 times at 209 °C in the transverse direction.
  • the stretched film was heat set at 239 °C to obtain a film having a thickness of 7.0 ⁇ m.
  • the film was prepared.
  • polyester (III) polyester (polyester (III)) and the above polyester (IV) were dried and molten in the separate extruders at 295 °C and 287 °C, respectively. Then, they were flowed together in the pipe and coextruded and quenched to obtain an unstretched film.
  • the unstretched film was stretched in the same manner as in Comparative Example 3 to obtain a film having a thickness of 7.0 ⁇ m.
  • the thicknesses of the layers of the polyester (III) and the polyester (IV) were 0.05 ⁇ m and 6.95 ⁇ m, respectively.
  • the surface which contacted to the stretching rolls was that of the layer of the polyester (IV).
  • the film was calendered. No white powder adhered to the calendering roll, and the magnetic tape had good properties.

Landscapes

  • Laminated Bodies (AREA)
  • Magnetic Record Carriers (AREA)
EP92103616A 1991-03-06 1992-03-03 Film de polyester pour bande magnétique Expired - Lifetime EP0504651B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP3040234A JP2970001B2 (ja) 1991-03-06 1991-03-06 磁気テープ用ポリエステルフィルム
JP40234/91 1991-03-06

Publications (2)

Publication Number Publication Date
EP0504651A1 true EP0504651A1 (fr) 1992-09-23
EP0504651B1 EP0504651B1 (fr) 1995-09-13

Family

ID=12575035

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92103616A Expired - Lifetime EP0504651B1 (fr) 1991-03-06 1992-03-03 Film de polyester pour bande magnétique

Country Status (7)

Country Link
US (1) US5441800A (fr)
EP (1) EP0504651B1 (fr)
JP (1) JP2970001B2 (fr)
KR (1) KR0184684B1 (fr)
CA (1) CA2062401A1 (fr)
DE (1) DE69204708T2 (fr)
MX (1) MX9200994A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0567279A1 (fr) * 1992-04-20 1993-10-27 Teijin Limited Film laminé de polyester et milieu d'enregistrement magnétique utilisant ce film comme substrat
EP0602964A1 (fr) * 1992-12-17 1994-06-22 Teijin Limited Film de polyester stratifié pour milieu d'enregistrement magnétique
EP1176005A2 (fr) * 2000-07-26 2002-01-30 Mitsubishi Polyester Film GmbH Film composite multicouches de polyester transparent et orienté biaxialement
EP1176163A2 (fr) * 2000-07-26 2002-01-30 Mitsubishi Polyester Film GmbH Film de polyester transparent et orienté biaxialement

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5626942A (en) * 1993-05-05 1997-05-06 Toray Industries, Inc. Polyester film and process for producing the same
GB9407803D0 (en) * 1994-04-20 1994-06-15 Ici Plc Polymeric film
CA2192695A1 (fr) * 1995-04-13 1996-10-17 Masatoshi Aoyama Composition au polyester et films fabriques a partir de celle-ci
US5795528A (en) * 1996-03-08 1998-08-18 Minnesota Mining And Manufacturing Company Method for making a multilayer polyester film having a low coefficient of friction
US5759467A (en) * 1996-03-08 1998-06-02 Minnesota Mining And Manufacturing Company Method for making multilayer polyester film
US8485460B2 (en) * 1999-12-28 2013-07-16 Teijin Limited Polyester film roll
US6908686B2 (en) 2002-11-26 2005-06-21 Dupont Teijin Films U.S. Limited Partnership PEN-PET-PEN polymeric film
US9558776B1 (en) 2015-12-11 2017-01-31 International Business Machines Corporation Durable coating for magnetic tape recording media
US11037592B2 (en) * 2017-12-07 2021-06-15 Toyobo Co., Ltd. Resin film with controlled youngs modulus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0238985A2 (fr) * 1986-03-26 1987-09-30 Hoechst Aktiengesellschaft Feuille en polyester à plusieurs couches pour supports d'information magnétiques
EP0312616A1 (fr) * 1987-05-01 1989-04-26 Toray Industries, Inc. Film en polyester et support d'enregistrement magnetique

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE238985C (fr) *
DE3414347A1 (de) * 1984-04-16 1985-10-24 Hoechst Ag, 6230 Frankfurt Traegerfolie fuer magnetische informationstraeger
JPS61239930A (ja) * 1985-04-17 1986-10-25 Teijin Ltd 磁気記録用ポリエステルフイルム
JPS62135339A (ja) * 1985-12-09 1987-06-18 Diafoil Co Ltd 磁気記録体用ポリエチレン−２，６−ナフタレ−トフイルム
JPH0625267B2 (ja) * 1985-12-17 1994-04-06 ダイアホイルヘキスト株式会社 高密度磁気記録媒体用ポリエチレン−２，６−ナフタレ−トフイルム
DE68925599T3 (de) * 1988-06-08 2004-09-30 Toray Industries, Inc. Biaxial orientierte Verbundfolie
US5051292A (en) * 1989-02-01 1991-09-24 Teijin Limited Biaxially oriented film of polyethylene-2,6-naphthalate
JPH058357A (ja) * 1991-07-04 1993-01-19 Diafoil Co Ltd 高密度磁気デイスク用ポリエステルフイルム

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0238985A2 (fr) * 1986-03-26 1987-09-30 Hoechst Aktiengesellschaft Feuille en polyester à plusieurs couches pour supports d'information magnétiques
EP0312616A1 (fr) * 1987-05-01 1989-04-26 Toray Industries, Inc. Film en polyester et support d'enregistrement magnetique

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0567279A1 (fr) * 1992-04-20 1993-10-27 Teijin Limited Film laminé de polyester et milieu d'enregistrement magnétique utilisant ce film comme substrat
US5431976A (en) * 1992-04-20 1995-07-11 Teijin Limited Laminated polyester film and magnetic recording medium using it as base film
EP0602964A1 (fr) * 1992-12-17 1994-06-22 Teijin Limited Film de polyester stratifié pour milieu d'enregistrement magnétique
US5702794A (en) * 1992-12-17 1997-12-30 Teijin Limited Laminated polyester film for magnetic recording medium
KR100270824B1 (ko) * 1992-12-17 2000-11-01 야스이 쇼사꾸 자기기록 매체용 적층 폴리에스테르 필름
EP1176005A2 (fr) * 2000-07-26 2002-01-30 Mitsubishi Polyester Film GmbH Film composite multicouches de polyester transparent et orienté biaxialement
EP1176163A2 (fr) * 2000-07-26 2002-01-30 Mitsubishi Polyester Film GmbH Film de polyester transparent et orienté biaxialement
EP1176005A3 (fr) * 2000-07-26 2002-03-20 Mitsubishi Polyester Film GmbH Film composite multicouches de polyester transparent et orienté biaxialement
EP1176163A3 (fr) * 2000-07-26 2002-03-20 Mitsubishi Polyester Film GmbH Film de polyester transparent et orienté biaxialement
US6420019B1 (en) 2000-07-26 2002-07-16 Mitsubishi Polyester Film Gmbh Multilayer, transparent, biaxially oriented polyester film

Also Published As

Publication number Publication date
KR0184684B1 (ko) 1999-04-01
DE69204708D1 (de) 1995-10-19
KR920017808A (ko) 1992-10-21
DE69204708T2 (de) 1996-05-09
CA2062401A1 (fr) 1992-09-07
EP0504651B1 (fr) 1995-09-13
MX9200994A (es) 1992-09-01
US5441800A (en) 1995-08-15
JPH04278345A (ja) 1992-10-02
JP2970001B2 (ja) 1999-11-02

Similar Documents

Publication Publication Date Title
EP0086302B1 (fr) Pellicule de polytéréphthalate d'éthylène, procédé de fabrication de celle-ci et moyen d'enregistrement magnétique fabriqué à partir de celle-ci
US5656356A (en) Biaxially oriented laminated polyester film
EP0572224B2 (fr) Film de polyester stratifié orienté biaxialement
KR100550081B1 (ko) 폴리에스테르필름및그제조방법
EP0504651B1 (fr) Film de polyester pour bande magnétique
US5366783A (en) Laminated polyester film for magnetic tape having specific surface properties
US6485810B1 (en) Biaxially oriented polyester film and flexible disk
EP0787579A1 (fr) Film multicouche orienté biaxialement
EP0893249B1 (fr) Film de polyester stratifié orienté biaxialement
US5529832A (en) Biaxially oriented laminated polyester film
EP0710547B1 (fr) Film de polyester stratifié biaxialement orienté
JP2001162750A (ja) 易接着性二軸配向ポリエステルフィルム
JP3310165B2 (ja) 積層フイルム
JP3323409B2 (ja) 積層二軸配向ポリエステルフイルム
JPH0542645A (ja) 積層ポリエステルフイルム
JP2944071B2 (ja) 複合化フィルムの製造法
JPH0542644A (ja) 磁気記録媒体用積層ポリエステルフイルム
JPH06234907A (ja) ポリエステルフィルム
KR100277051B1 (ko) 2축배향 적층 폴리에스테르필름
JP3217338B2 (ja) 複合配向ポリエステルフィルム
JP3306292B2 (ja) 二軸配向積層ポリエステルフイルム
JPH0676268A (ja) ベルヌーイ型フロッピーディスク用ポリエステルフイルム
JPH07266521A (ja) 積層二軸配向ポリエステルフイルム
JPH0468144B2 (fr)
JPH0531859A (ja) 複合配向ポリエステルフイルム

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT LU NL

17P Request for examination filed

Effective date: 19930303

17Q First examination report despatched

Effective date: 19940211

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT LU NL

REF Corresponds to:

Ref document number: 69204708

Country of ref document: DE

Date of ref document: 19951019

ET Fr: translation filed
ITF It: translation for a ep patent filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19990331

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20001001

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20001001

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20020212

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20020227

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 20020304

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20020321

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030303

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030303

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031001

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031127

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050303